Finish paint films applied on surfaces, such as automobile bodies and facing components, show undesirable signs of deterioration including discoloration, fading, and blistering following long years of weathering.
Although the deterioration of conventional finish coat is effectively prevented by waxing or other means, such maintenance increase the user's work load.
To counter such inconvenience, several tests have been proposed to improve weatherability by forming a fluoride resin paint on a finish coat.
Japanese Patent Kokai Application No. 61/197074 describes an automobile finish coating in which a clear paint, mainly composed of a fluoride polymer having the formula (I), is applied on a solid color finish coat using a dry-on-wet process. ##STR2## In formula (I), X is a fluorine atom or chlorine atom, and R is a hydroxyalkyl group or carboxyalkyl group. Japanese Patent Kokai Application No. 63/59373 describes a method of metallic finish involving painting a clear top coat on a metallic base coat. The top coat consists of mainly fluorine-containing polymer (A) and cross linking agent, and is soluble in organic solvents. Fluorine-containing polymer (A) incorporates fluoro-olefin, hydroxyl, and carboxyl groups, and has an average molecular weight of from 3,000 to 20,000 and from 1 to 40 wt% fluorine atoms. These conventional methods to form protective layers have been viewed as a way to further improve weatherability, such as resistance to discoloration and weathering, but these methods have had a problem with respect to adhesion.